A gaseous nitrous acid generating device and its process

Abstract

The invention provides a gaseous nitrous acid generating device and a technology thereof. The device comprises a mass flow controller and a gas transportation pipeline which are connected with a compressing steel cylinder, an output end of the mass flow controller is connected with a spiral pipe gas generator, the spiral pipe gas generator is sequentially connected with a glass spiral pipe and a gas-liquid separation bottle which are integrally formed in the spiral pipe gas generator through a gas input pipe, a bypass input pipe is formed in the gas input pipe of the glass spiral pipe, and the bypass input pipe is connected with a dilute sulphuric acid reagent bottle and a sodium nitrite solution reagent bottle through a three-way valve connected with the bypass input pipe and liquid transportation pipelines at the two ends of the three-way valve and peristaltic pumps respectively; the upper end of the gas-liquid separation bottle is provided with a gas outlet, and a liquid transportation connector at the lower end of the gas-liquid separation bottle is connected with a waste liquid bottle through a liquid transportation pipeline and a peristaltic pump. According to the gaseous nitrous acid generating device and the technology thereof, the flowing path of a mixed solution is lengthened through the glass spiral pipe in the spiral pipe gas generator, gas and liquid are fully mixed in a turbulent mode, nitrous acid molecules spread to the gas phase, separation is achieved in the gas-liquid separation bottle, and high-purity gaseous nitrous acid is produced.

Description

technical field [0001] The invention belongs to the technical field of chemical material preparation, and relates to a preparation device for nitrogen-containing trace gas, in particular to a gaseous nitrous acid generating device and a process thereof. Background technique [0002] Gaseous nitrous acid (HONO), an important trace gaseous pollutant, has become a hotspot in atmospheric chemistry research because it is the main primary source of OH radicals. In recent years, scientists have carried out a lot of research work on gaseous nitrous acid measurement technology, gaseous nitrous acid generation and reaction mechanism, etc. These works urgently need a reliable source of gaseous nitrous acid. [0003] Due to the strong chemical activity of gaseous nitrous acid, which can react or adsorb on various surfaces, conventional gas preparation methods such as permeation tube and diffusion tube technology are difficult to apply, and laboratories usually use nitrite and acid to re...

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Problems solved by technology

If the reaction between particles and oxalic acid vapor is used, this method requires strict control of experimental conditions such as humidity, and the repeatability and stability are not ideal.

A similar method also uses nitrite and hydrochloric acid mist reaction, NH 4 NO 2 coating with N 2 This kind of method of preparing gaseous nitrous acid by gas-solid reaction has relatively high requirements on the control of experimental conditions and tightness, and the consumption and replacement of solid reagents will interfere with the stability of the gas, so it is rarely used

[0005] In general, the existing devices and processes for preparing gaseous nitrous acid have more or less problems in terms of technical complexity, concentration control methods, gas purity and stability, etc. In view of these defects, it is urgent to propose better solution

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